I'm afraid I don't know about the rotary switch for sure but there's no electronics shown in JTIS.
I don't understand just one injector pulse.
Is there any chance it is an artefact of some sort?

 

OK, I ran all tests on the Digital Transmission Rotary Switch.

After checking all switches and positions as per JTIS, I have concluded those are OK but I still wonder about the "4-Bit Binary Coded Signals" being sent to the TCM "Over 4-Wire Parallel Interface".

Since all I am taking are Voltage Readings which are correct as per JTIS, I have no way of testing those digital signals from Rotary Switch to TCM or from TCM to ECM.

Since I did have a P1797 Code at one point - CAN TCM/ECM Circuit Malfunction, I wonder if there is a Rotary Switch to TCM communication Problem, or TCM to ECU communication problem.

I think it is the TCM so I will take to Jag and have tested.

Thanks a million to everyone for their help.

Chuck

 

I'm not convinced about your diagnosis.
The 'stability control' error needs sorting as does the one injector pulse.

I know this sounds like straw clutching but dirty TPS contacts have caused 'stability control' errors and RP (GOK why)
It costs nothing to clean up the connector on the throttle body.
Still no codes?

 

First I would check that power is going to each of the fuse/relay boxes this would verify that you high power protection fuses are good. Now your comment about the burnt smell from under the hood concerns me but I will move on because it could be from the starter. You said that this is a 1997 MY car and it is equipped with a Nikasil engine. You commented that the engine is turning, is it turning freely with no compression pulse? If this is correct I would say you are experiencing cylinder washing. What is confusing me is that the light on the shifter panel at times were not lit the car will not start unless it sees the shifter in “P” or “N” and with the lights out it will not see it. This could be just a cable adjustment at the shifter. You comment no pulse in “P” but does it in “N”? Your suggestion of the engine being replaced can confuse matters I would get the engine number and see if it was changed out.

A low battery will give you false readings so I am not sure I would be chasing them. I would recharge the battery, do a hard reset, reset the codes and verify that you have spark and fuel. I would then check to see if your car is equipped with a Nikasil engine and if it is use the procedure attached by adding oil to the cylinders to get it started.

Link No Start JagRepair.com - Jaguar Repair Information Resource

Link Nikasil Cylinder Wash JagRepair.com - Jaguar Repair Information Resource

Link Identify Nikasil JagRepair.com - Jaguar Repair Information Resource

I could be all wrong on this but I thought I would put my $.02 worth of advice in the pot.

 

After playing with all electrical connectors under the hood, pow she came to life and ran for 8 seconds then died.

So I decided to play with the two connectors on front of each cam cover (I Thought these were Cam Sensors) so I unplugged the passenger side and plugged it back in, nothing but one injector pulse and no start.

I then unplugged the driver side and plugged it back in, and she started right up for 2 seconds then died. So I did it again with same results every time (Did it 7 times) So I think this unit is the VVT Solenoid and possibly is bad?

Please let me know your thoughts on how these solenoids can effect starting and who is the cheapest for a new one.

Thanks,

Chuck

PS: Guys, not being ungrateful, but please lay of the Nikasil diagnosis, the engine turns normally and is not flooded. Thanks

 

While the ECM will record and report a VVT solenoid issue I cannot imagine that it would affect starting.

Might pay special attention to the Ignition Relay in the ECM/TCM enclosure. Since all of your testing refers to connectors I wonder if that includes PCM/TCM connectors. If not, try that . . . with the battery disconnected.

. . . and your car does have 2 Ignition Modules driving 4 coils each. They are mounted on the firewall. Did they get included in the connector review?

 

Check any ground points you can see. I'm wondering if you're just physically moving the engine or a harness enough to temporarily make an earth.
We had one car that would only run with one wheel jacked up for just this reason.
Like test point I can't see how defective VVT would have such a drastic effect.
You could also check ECM grounding using this
https://www.jaguarforums.com/forum/x...-ground-90481/

 

Have you checked both fuses to the fuel pump? One is for the key start power and the other is for constant power. I know you said you had fuel pressure but wanted to know if this could be part of the problem.

Link JagRepair.com - Jaguar Repair Information Resource

As for the Nikasil I was concerned when you stated that the engine just spins “no pulse” the results of cylinder washing no compression not flooding. The only way to know is to take a compression test. The link also provides a way to check the engine block #.

Understand we are inside the computer not at your location with the advantage of hands on. Just trying to help!

 

I took the liberty to reread your entire post with the hopes I was not on the track and you were correct I was not.

If your shifter illumination module is illuminating between the “P” & “D” then the transmission control switch and the transmission control module are seeing each other and I assume you verified the positions with the indications.

You indicated that you did swap out the relays first eliminating the possible bad relay. We have had a situation in the past when the engine management fuse box had a connection problem internal this could be a problem.

The fact that you got is started even for a moment is a good thing but what is causing it shutting down and or prevent the start. I would pull the engine management fuse box and eliminate it from the equation.

 

Ok Guys and Gals, I guess I really am a stubborn one-track minded SOB (At least that's what my woman tells me). But it paid off Big-Time!!!

Here is what I found:

After playing with the electrical connectors on the engine and narrowing it down to the drivers side VVT Solenoid, that when I unplugged it and plugged it back in, she would start for half a second.

So just for the heck of it tonight I decided to measure resistance from each wire back to the ECM. Red/Black 3 Ohms, White/Blue 60 Ohms!!!!

So I ran a jumper wire from the ECM to the Passenger side VVT Solenoid White/Blue wire since both VVT Solenoids share the White/Blue wire as a common back to the ECM.

She fired right up and purred like a kitten.

So it seems there is high resistance somewhere between ECM and those White/Blue wires, so I just ran a permanent jumper wire from passenger side VVT White/Blue wire back to ECM, and drove her around the Neighborhood Twice!!! ( I even tossed in the dog for the second ride)

WOW, WOW, WOW!!!

I have to say, the factory reflash must have done something substantial to her power curve because my 2001 KX8 never pulled this hard when I stomped on her. It seriously pulls like 350HP and I believe it is due to the factory reflash.

That you all so much for your help and have a great weekend!!!

Cheers,

Chuck

 

I'm delighted - we had nothing to do with your success sadly.
I'm completely unable to explain why this should happen - I thought you could disconnect the VVT solenoid with no ill effects.
Apart from the connector to the solenoid I don't see another that could be bad so a real mystery.

 

I have been driven her around every day for the past week and a half without any problems other than the usual ABS/Stability thingy.

Yesterday while driving the check engine light came on and then a while later the poor performance message came up. So I parked her and checked the codes.

P171 Bank 1 Lean
P174 Bank 2 Lean

I cleared the codes and now she will not start up at all just like the problem I had before.


No Spark, and only One (1) Injector Pulse (If I remove and reinstall the connector from Drivers Side VVT Solenoid)

I went through the Large 60 something engine harness connector on top rear of engine and measured every singe wire going through it for proper resistance.

All check out at .08 Ohms from one side of connector to other side( After I cleaned and lubed the contacts).

I replaced the fuel filter just for the heck of it.

I really think it is an electrical problem somewhere, or the computer is bad (I noticed there were some greasy fingerprints on it when I inspected it the first time).

Please help.

Thanks a million,

Chuck

 

Straw clutching needed.
Have you cleaned all the connectors on the ECM ?
Can you probe at the ECM for continuity for the other VVT wires ?

 

Ok, I have checked, cleaned, and lubed all electrical connections and wiring under the hood and still only one pulse and a sputter after disconnecting and reconnecting the Drivers side VVT solenoid.

OBD2 is now showing code P1227 Limp Home Solenoid.

I checked the ECM at OBD connector for proper voltage and proper grounds, and everything is ok.

Here is the last 6 digits of the VIN: 001649

Please tell me what is the correct ECM part number for this car. I believe someone may have changed the ECM and it could be the wrong one?

Here is the ECM in there now: LJA1410AH

With all these different codes popping up since I got her, and all wiring seems OK, I strongly believe the ECM is Bad.

Maybe I should take it apart and check for bad solder joints since she ran great for one week straight without any problems.

Also, if I need to purchase another ECM, does it need to be programmed by the dealer?

Thanks,

Chuck

 

Chuck,

Look in the boot, on the rear wall below the boot latch. There should be a VCATS label there with all the module part numbers. Each will be followed by a software level, in the form /102, for instance. Get that number and let us know what it is, then I can tell whether the one you have is good for your car or not.

Personally I would replace all the relays under the cover by the ECM enclosure, including the one in the small fuse box. Also replace the relay closest to the engine in the fusebox over the LF tire. At your cars age, they can be causing havoc, especially intermittently.

Given all that's happened, clear all the fault codes, disconnect the battery for a few minutes, reconnect the battery and then turn the ignition on. Look at the shifter and see if the "P" is illuminated. You might as well check the instruments and see if any messages are displayed then, too. [other than door open, etc.]

If the "P" isn't lit or messages are present, let us know that and what they are.

If no messages, get out and lock the car down with the remote for a couple of minutes. Unlock the car and attempt starting. Let us know what happens at that point.

Cross your fingers.....

 

Hopefully this issue has finally been resolved. Took car to Jaguar they could not figure it out after 1 week. They were going to call England to help. Luckily mechanic was very honest nice man and we worked together to figure it out. After having computer rebuilt still no start. Traced it to voltage coming from crank sensor disappeared after connecting back to computer. Ran jumper wires from crank sensor back to computer and she fired right up. So it appears there is high resistance or bad connection somewhere in the wiring harness. Been driving her for about 1 week now without any problems. Thank you everyone for your help if there are any changes I will let you know. Chuck

 

Nasty one - very unhelpful OBD codes. I wonder why you didn't get CPS fault codes?

 

You mean PDF. I posted the link a few months ago. Don't ask me where

 

Yes I did mean PDF - trust you to loose it !

 

Crank sensor issue is resolved and been driving her every day. Only warning is ABS/TRAC but Jaguar guy told me it was pump motor connections and right front sensor leads so not worried about that.

She now has P174 and P171 again and they keep popping back after driving for about half a day after I clear them.

She runs and drives great and is really fast.

But now she also displays ENGINE FAULT at operating temperature occasionally and cruise control does not work.

I have traced the majority of her problems to that stupid idiotic Main Electrical connector on top rear of engine above the bellhousing. I am planning on replacing the entire connector with something else, or heat shrink butt connector every one of the seventy or so wires just to eliminate any possibilities. (I do not plan on yanking the engine out at any time so it is unnecessary)

Once I do that I will need to see what she throws up for codes.

Question: What causes ENGINE FAULT and there are no codes?

Thanks,

Chuck